Hydro Village Grid

What it is

Village hydro can run in an isolated mode but similar to the other village grid systems, more than one generating plant can be used. Hydro Village Grids have different energy outputs, and classified mainly as Pico Grid (2kW-10kW), Micro Grid (10kW-1’000kW) and Mini Grid (1MW to 2MW). System size varies depending largely on the local characteristics of the river, such as the water flow availability (litre/sec) and gradient (head). Since water is running constantly in the riverbed, using hydro turbine is a reliable energy solution throughout the year. System design and maintenance takes into account changing water levels between rainy and dry season. The systems are small and do not have an impact on the local biosphere but sill can generate electricity for several hundred households.

How it works

The power available in a river or stream depends on the rate at which the water is flowing, and the height (head) which it falls down. Hydro schemes are classified by the output power which they produce:

Large scale: 2 MW and above

Mini: 100 kW to 2 MW

Micro: 5 kW to 100 kW

Pico: less than 5 kW

The core of a micro-hydro scheme is the turbine, which is rotated by the moving water. Different types are used, depending on the head and flow at the site.

Applications

Many micro-hydro schemes are remote from the main grid, and a local grid is then constructed to distribute the electrical power.

The output from the generator must match the demand for electric power, otherwise the voltage and frequency can vary suddenly, which can damage some electrical equipment. The demand for power in an off-grid system is often very variable, because people switch lights and machines on and off, so the supply from the micro-hydro system must be varied to keep close control. This can be done by varying the water flow, or by using an electronic load controller.

Micro-hydro schemes can be connected to a mains grid if available.

In some micro-hydro schemes, the rotating shaft directly drives machinery such as a grain mill.